Long Lake

Long Lake sits at a C on the grading scale — not impaired, not pristine, with summer measurements that vary year to year. Clarity is the limiting factor — phosphorus is reasonable but suspended particles or algal cells keep water transparency below Wisconsin norms.

At a TSI of 51, Long Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. A maximum depth of 17 ft puts Long Lake in the middle of Wisconsin's depth distribution. At 273 acres, Long Lake fits the Wisconsin median for monitored lakes, with partial shoreline records. Within Polk County's 74 graded lakes, Long Lake ranks 38 — below the local median, though not at the bottom.

An invasive species record — Banded Mystery Snail — has been logged at Long Lake; Wisconsin DNR maintains the official infested-waters list. Bass fishing is part of the appeal: the species list runs to 3, anchored by largemouth and/or smallmouth bass. Public access is available — the lake is on the Wisconsin DNR public-access list. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.